This invention relates to a socket for an electric part in which a press-down force is applied to an electric part body placed on a socket body, and more particularly to an electric part press-down device for maintaining a contacting condition between the electric part and the socket body.
Japanese Laid-Open Utility Model Publication No. Sho 60-57135, for example, discloses a typical electric part socket in which a press-down force is applied to an electric part placed on a socket body. In this conventional electric part socket, a basal end of a pressing cover is pivotally attached to one end of the socket body, an electric part body (or terminals) is pressed down by closing the pressing cover onto an upper surface of the socket body and thereby flexing contacts of the socket body downwardly and obtaining a contacting pressure against the terminals due to the reaction force of the contacts. A lock lever pivotably attached to the other end of the socket body is brought into engagement with a free end of the pressing cover to maintain the closing condition and thus to maintain the contacting condition.
However, in the socket thus constructed, the socket body and the pressing cover are generally the same in size, and when the pressing cover is closed onto the upper surface of the socket body, the electric part is almost entirely covered with the pressing cover and held in a half closed condition between the pressing cover and the socket body. As a result, heat of the electric part cannot be effectively radiated, and therefore the electric part is damaged by accumulated heat.
When the electric part is placed on and removed from the socket body, it is necessary to pivot the pressing cover by more than 90 degrees in order to open the upper surface of the socket body and, therefore, it becomes difficult to use an automated machine to open and close the pressing cover.
Since an upwardly directed force acts on a central portion of the pressing cover due to the reaction force of the contacts, the pressing cover becomes warped in a short period of time due to heat.
Also, pivot end and the free end of the pressing cover do not press down against the electric part simultaneously (i.e. the electric part is pressed against first by the pivot end of the pressing cover), the electric part is caused to jump, thereby giving rise to poor contact between the terminals and the contacts.